Electromagnetic device to prevent rotation of bobbins



March 10, 1925.-

w. H. WAKEFIELD ELECTROMKGNETIC DEVICE TO PREVENT ROTATION 0F BOBBINS Filed June 19, i924 Patented Mar. .10, 1925.

UNITED STATES PATENT OFFICE.

WALTER H. WAKEFIELD, 0F WORCESTER, MASSACHUSETTS, ASSIGNOR TO CROMP TON & KNO'WLES LOOM WORKS, 013' WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

ELECTROMAGNETIC DEVICE TO PREVENT ROTATION OF BO'BBINS.

To all whom it may concern:

Be it known that I, WALTER H. lVAKE- FIELD, a citizen of the United States, residing at Worcester, in the county of Worcester and State of Massachusetts, have invented a new and useful Electromagnetic Device to Prevent Rotation of Bobbins, of which the following is a specification.

This invention relates to weft replenishing mechanism for looms and more particularly to devices for preventing the rotation ofbobbins on their axes as they await transfer.

It has been found in practice that when bobbins are required to remain in the usual multi-color weft replenishing mechanism for any length of time prior to transfer, they rotate on their own axes and the filling ends which lead to the thread holder become entangled. This frequently results in breaking the thread at the time of transfer so that the shuttle is not properly threaded.

It is the general object of this invention to overcome this rotation of the bobbins by making use of the magnetic'properties of the steel rings usually found on the bobbins used in weft replenishing looms and to that end I have provided magnetic surfaces so positioned as to attract the rings of the bobbins and to hold the latter against vibration.

Accordingly, it is the principal object of my invention to arrange a series of normally energized electro-magnets along the path of travel of the bobbins which shall be deenergized to release the bobbins at the time they are called upon to descend under the action of the replenishing mechanism.

A further object of my invention is to provide a series of electro-magnets so energized that adjacent poles are, of opposite polarity, adjacent poles being arranged to engage the steel rings of adjacent bobbins so that the steel rings of each pair of bobbins will form part of a closed circuit for the magnetic field of the associated pair of electro-magnets. I

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawing, wherein one convenient form of my invention is illustrated,

Fig. 1 is a side elevation of a two color replenishing mechanism having my invention applied thereto and shown as viewed from the central portions of the loom,

Fig. 2 is a vertical section on line 22 of Fig. 1,

Fig. 8 is a horizontal section on line 33 of Fig. 1,

Fig. 4 is a fragmentary horizontal sectiocili on line 44 of Fig. 1, looking down, an

Fig. 5 is a fragmentary view of a part of the magnetic element with bobbins, indicating the magnetic fields.

Referring to the drawing it will be seen that I have provided a frame 10 from which extend flanges 11 and 12 to form the outer boundaries of the two bobbin compartments. Slidably mounted for vertical motion on the frame 10 are slides 13 and 14, respectively, which are formed with upper and lower lugs 15 and 16, respectively. An angularly and longitudinally movable rod 17 under control of the box mechanism (not shown) has extending therefrom fingers 18 which will be positioned for engagement with the lugs of one or the other of the slides 13 and 14. At the bottom of each bobbin compart-, ment is located a cradle, one of which is shown at 19 in Fig. 1 and these cradles are arranged to be oscillated on their axes by the slides at the time the weft detector (not shown) indicates substantial weft exhaustion. The flanges 11 and 12 are associated with flanges 20 and 21, respectively, to form bobbin compartments 22 and 23, respective ly, in which are located the bobbins W. The matter thus far described is of the usual construction and for a more complete description reference may be had to Patent No. 1,030,748.

My invention relates more particularly to electro-magnets which are associated with the interior flanges 20 and 21. In carrying out my invention I provide a bar 30 of magnetic material and form the same with a plurality of extensions or pole faces 31 spaced apart to receive coils 32 which lie between the poles 31 and are wrapped around the central portion of bar 30. In order to receive the pole faces I have pro- Application filed June 19, 1924. Serial No. 721,120. ""4 o-;

vided each of the interior flanges 20 and 21 with a series of recesses indicated at 33, these recesses being preferably larger than the end section of the poles, so as not to contact with the same. The bar is held to the frame by means of screws 31 and 35 which pass through upper and lower extensions thereof, respectively, and are secured in the frame 10 in such. a way as to space the poles from said frame substantially as shown in Figs. 2 and In order to energize the coils I have provided a battery or other source of current 36 which by means of wire 37 is connected to contact screw 38 which is mounted on but insulated from the frame 10, as shown at 39. Intermediate the slides 13 and 14; I have provided a contact slide 10 from which extends lug 11. The contact slide is guided in bearings 12 and 13, respectively, and has secured to the lower end thereof a resilient contact spring 44 which is normally positioned for contact with screw 38 when the slide is held in lowered position. Secured to rod 17 is an 21111145 having a broadened finger 16 which as shown in Fig. 4. is positioned for engagement with lug L1 in both longitudinal positions of the rod 17.

I have found that the poles are considerably stronger if the coils are energized in such a way that adjacent ends have the same polarity and in order to bring about this result I connect up the coils substantially as shown in Fig. 2 where it will be seen that current rises through the first, third, fifth and seventh coils but passes downwardly through the intermediate coils, the result of this is to create magnetic fields substantially as shown in Fig. 5 where it will be seen that alternate poles 81 are north and the intervening poles are south.

The poles are preferably positioned apart a space equal to the diameter of the rings of the bobbins as shown in Fig. 5. where it will be seen that the steel rings of the bobbins, in being in contact with each other, form a closed circuit for the magnetic lines of force set up by adjacent poles. the result of which is to hold the bobbins in pairs not only to the pole faces 31 but also to each other.

Under normal operation the slide is in lower position as shown in Fig. 2 and the cradles are empty. As the boxes change the fingers 18 will be moved to register with one or the other of the vertical slides 13 or 14 but in whatever position the fingers 18 may be, finger 46 will always be positioned' for engagement with lug 41. It is to be understood that fingers 18 have a downward motion on every second or nondetecting pick of the loom and that the fingers move upwardly on indicating picks. So long as there is snfficient yarn in the active shuttle for continued weaving the linger 16 will not. be raised, and spring l4 will contact with screw 38 to complete the following circuit: battery 36, wire 4-7, to the bottom of the lowest coil 82, wire 18 to the top of the next coil 32, etc., to wire 19, screw 34-, frame 10, slide 40, contact spring l i, screw 38, wire 37 back to battery as, The coils-are thus energized and the rings of. the bobbins are attracted to the pole faces. At the time of weft indication, finger 16 will be raised to elevate slide 10 and lift spring 1 1: away from screw The circuit is thereby broken, the coils become de-energized. and the bobbins are permitted to fall as the cradle rocks to receive the lowest bobbin. Immediately thereafter shaft 17 is given a clockwise movement and finger 4:6 returns to permit slide 40 to assume normal position, the result of which is to establish the circuit. In this way the bobbins are released for a brief period only at the time the indication is given, this interval being independent of the time vertical slides 13 or 1 1 are in raised position.

In order to return slide 40 to normal position, I may provide the same with an extention 50 having a projection 51 positioned to engage bearing 43 to stop the slide. The extension may have a notch 52 to receive the upper end of coil spring the lower end of which is held by a clip 54 retained by screw 55. The tension of spring 53 normally holds projection 51 against the'bean. ing so as not to interfere with the action of contact spring 44.

From the foregoing it will be seen that I have provided electro-magnetie means for preventing the rotation of bobbins by making use of the magnetic properties of the. rings usually provided on bobbins for automatic looms. It will further be noted that the magnets are connected to have adjacent poles manifest opposite polarity and that the poles are spaced apart a distance substantially equal to the diameter of the rings so that the latter are attracted not only to the magnets but also to themselves. It will further be noted that the magnets are deenergized for a brief period only and the attraction of the rings of the bobbins is practically continuous and independent of the length of time elapsing between indication of weft exhaustion and transfer of a fresh bobbin.

Having thus described my invention it will be apparent that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclosedbut what I claim is:

1. In a weft replenishing mechanism for bobbins, each of which has aportion thereof formed of magnetic material, magnetic means to act on the magnetic material. of the bobbins to prevent vibration thereof.

2. In weft replenishing mechanism for operating on bobbins having portions formed of magnetic material, a compartment for the bobbins, and electro-magnctic means associated with the compartment to attract the magnetizable portion of the bobbins.

3. In a weft replenishing mechanism for operating upon bobbins a portion of which are magnetizable, electro-magnetic means under control of the replenishing mechanism to attract said magnetizable portion of the bobbin and prevent rotation thereof.

4. In a weft replenishing mechanism for operating upon bobbins a portion of each of which is formed of magnetizable material, a guideway for the bobbins and means to create a magnetic field on one side of the guideway to attract the magnetizable portions of the bobbins to prevent rotation of the bobbins.

5. In a weft replenishing mechanism for operating upon bobbins having magnetizable portions, means to create a magnetic field adjacent the magnetizable portions of the bobbins, and means to de-energize said field at the time of indication of substantial weft exhaustion.

6. In a weft replenishing mechanism for operating upon bobbins having magnetizable portions, means to advance the bobbins to ward transfer position, means to create a normally energized magnetic field to attract the magnetizable portions of the bobbins,

and means to de-energize the field at the time the bobbins move toward transfer position.

7. In a weft replenishing mechanism for operating upon bobbins having magnetizable portions, a guideway for the bobbins, a series of electro-magnets disposed along the guideway, adjacent magnets having opposite polarity and being spaced apart a distance substantially equal to the distance between bobbins in the guideway.

8. In a weft replenishing mechanism for operating upon bobbins having magnetizable portions, a plurality of bobbin compartments, means to create a magnetic field adjacent each compartment, means to permit movement of the bobbins of each compartment toward transfer position, and means to de-energize the magnetic field of all the compartments when the bobbins of any compartment move toward transfer position.

9. In a weft replenishing mechanism for bobbins each of which has a portion thereof formed of magnetic material, electro-magnetic means normally acting on the magnetic material of the bobbins to prevent vibration thereof, and means to de-energize the electromagnetic means to release the bobbins for a brief interval at the time of indication of weft exhaustion, said interval of time being independent of the time elapsing between indication of weft exhaustion and subsequent transfer.

In testimony whereof I have hereunto afiixed my signature.

WALTER H. WAKEFIELD. 

